Grinding wheel spindle reciprocating apparatus



8 1941- c. c. ALVQRU 2 1 GRINDING WHEEL SPIHDLE RECIPROCATING MWARATUSFiled June 8, 19159 3 Shwm-Shwt l 8, 1941 m. a. mvonn 2 K GRINDING WHEELSPINDLE RECIPROCATING APPARATUS Filed Jun 8, was s Sheets-Sheet 2GRINDING WHEEL SPINDLE RECIPROCNTIMG APPARATUS Filed June 8, 1939 3Shoots-Shem. 5

Patented Apr. 8, 1941 I UNITED STATES PATEN OFFICE ammo. wnanr. srmpnaaacrraoca'r- ING APPARATUS" 1Claim.

This invention relates to grinding machines, and more particularly to agrinding wheel spindle reciprocating mechanism.

One object of the invention is to provide a simple and thoroughlypractical mechanism for reciprocating a grinding wheel -.spindle axiallywithin its bearings. Another object of the invention is to provide agrinding machine with a spindle reciprocating mechanism, in which thegrinding wheel spindle may be oscillated or re-- ciprocated through anadjustable stroke. Another object is to provide a wheel spindlereciprocating mechanism which is driven independently relative to thespindle drive, and which is provided with adjusting means whereby thereciprocatory stroke of the spindle may be varied during rotation of thewheel spindle. Other objects will be in part obvious or in part pointedout hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts, as wfll beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claim.

In the accompanying drawings, in which is shown one of various possibleembodiments of the mechanical features of this invention,

Fig. 1 is a vertical sectional view through a grinding machine wheelslide showing the wheel spindle reciprocating mechanism;

Fig. 2 is a horizontal sectional view, on an enlarged scale, takenapproximately on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary sectional view taken approximately on the line3-4 of Fig. 1;

Fig. 4 is a fragmentary sectional view taken approximately on the line4-4 of Fig. 1, showing the mechanism for adjusting the length of thegrinding wheel reciprocatory stroke;

Fig. 5 is a fragmentary cross sectional view taken approximately on theline 5-5 of Fig. 2;

Fig. 6 is a fragmentary sectional view taken approximately on the line8-4 of Fig. 1, showing the length of the reciprocatory stroke of thegrinding wheel:

Fig. 'l is a fragmentary sectional view taken approximately on the line'I-'l of Fig. l; and

Fig. 8 is a cross sectional view taken approximately on the line 8-8 ofFig. '7. a

A grinding machine has been illustrated in the drawings comprising abase III which supports a transversely movable wheel slide II on a V-wayI 2 and a flat way It on the base it. The wheel slide ll supports arotatable grinding wheel which is mounted on one end of a rotatablewheel spindle IS. The spindle I8 is journalled in suitable bearings l1and I8 within the wheel slide 1 I. The right-hand end of the wheelspindle is (Fig. 1) is provided with a driving pulley l9 which ispreferably of a multiple V-grooved type. The wheel spindle l6 may bedriven in a manner to be hereinafter described.

A wheel feeding mechanism is provided for manually feeding the grindingwheel l5 toward and from the work piece, which comprises a half nut 22depending from the under side of the wheel slide H. The half nut 22meshes with or engages a rotatable cross feed screw 23 which may berotated by any of the well known wheel feeding mechanisms such as, forexample, that shown in the expired United States patent to C. H. NortonNo. 762,838 dated June 14, 1904. This mechanism has not been illustratedin detail in the present application since it is not considered to be apart of the present invention. Consequently, for further details ofconstruction, reference may be had to the above-mentioned prior patent.

A grinding wheel driving mechanism is provided whereby the grindingwheel I5 may be rotated at a normal grinding speed either for a grindingoperation or for a grinding wheel truing operation, or the wheel may berotated at a very slow speed below the normal grinding speed for apolishing operation, or the grinding wheel may be held against rotationfor a honing operation and automatically indexed after each successivehoning operation to present a new abrading surface for the nextoperation.

The grinding wheel I5 is preferably driven by a motor driven mechanismcomprising an electric motor 25 which is mounted on an adjustablesupport 26. The adjustable support 26 is provided with a dovetailedslideway 21 which mates with a correspondingly shaped way on top of acasing 28 which supports the gear driving mechanism. The casing 28 isadjustably mounted on the upper surface of the wheel slide H. The motor25 is preferably a variable speed motor, such as a DC motor whichreceives its power from the power lines 29. As diagrammaticallyillustrated, a switch 30 serves to stop and start the motor 25, and aspeed control device, which is diagrammatically illustrated as arheostat 3|, serves to adjust and vary the speed of the motor 25. The

motor 25 is provided with a driving belt which is connected by means ofa multiple V-belt 32 with a multiple V-grooved pulley 33 mounted on theouter end of a motor shaft 34. The V-belts 32 are connected with aV-grooved pulley 35 mounted on the outer end of a shaft 36 which isJournailed in a bearing 31 in the casing 28. The inner end of the shaft36 is keyed within a sleeve or bushing 38 which is in turn rotatablysupported by anti-friction bearings 39 which are also supported by thecasing 28. The sleeve 38 also supports a bearing bushing 46 which servesas a bearing support for a rotatable shaft 4|. The outer end of theshaft 4| is journalled in a bearing 42 carried by the casing 28. Amultiple v'-grooved. driving pulley 43 is mounted on the outer end ofthe shaft 4| and is connected by multiple V-belts 44 with the multipleV-grooved pulley I9 mounted on the outer end of the wheel spindle I6.

An adjusting screw 48 is rotatably supported in a bearing 49 which iseither formed integral with or fixedly mounted on the casing 28. Thescrew 48 is held against endwise movement relative to the bearing 49 andthe screw 46 meshes with or engages a nut 56 depending from the underside of the motor support 26. By adjusting the screw 48, the position ofthe motor mounting 26 may be adjusted so as to properly tension thedriving belt 44. A similar adjustment is provided for the casing 28. Adovetailed slideway 52 is formed between the casing 28 and the wheelslide A similar nut and screw ad- ,iustment is provided between thecasing 28 and the wheel slide II by means of which the multiple v-belt32 may be tensioned as desired.

In order to obtain a fast speed of the grinding wheel I for a normalgrinding operation or for turing the grinding wheel, it is desirable toprovide a suitable connection whereby the shaft 36 may be connecteddirectly with the shaft 4|. The slidably mounted clutch 55 is slidablykeyed onto the shaft 4|. The clutch 55 is moved toward the left (Fig. 2)so that the clutch teeth 56 of the slidably mounted clutch member 55engage clutch teeth 51 formed in the end of the rotatable sleeve 38which is keyed to the shaft 36 so that power is transmitted directlyfrom the shaft 36 to the. shaft 4| and through the pulley 43 andmultiple V-belts 44 to rotate the wheel spindle pulley I9. the wheelspindle I6, and the grinding wheel l5 at a normal, relatively fastgrinding speed.

The clutch member 55 is preferably arranged so that it may be readilycontrolled from the operators station in front of the machine. A ,vokedmember 66 is supported on a rock shaft 6| which is journalled inbearings 62 and 63 in the housing or casing 28. The lower end of theyoked member 66 is provided with opposed studs or shoes 64 which ride ina groove 65 formed in the periphery of the clutch member 55. The shaft6| is provided with a gear segment 66 which meshes with a gear segment61 carried by the shaft 68 which is rotatably journalled in a bearing 69formed in the casing 28. The outer end of the shaft 66 is provided witha manually operable actuating handle 16. Formed integral with the gearsegment member 66 is adownwardly extending arm 1| which is provided witha pair of apertures 12 and 13 which are arranged to be engaged by meansof a spring-pressed detent such as a ball 14 to readily locate the gearsegment 66 in one of two positions, namely with the clutch teeth 56 inengagement with the clutch teeth 51 or with clutch teeth 16 inengagement with clutch teeth 11 formed integral with a rotatable bushing18 which forms a part of a slow speed driving mechanism to behereinafter described. As shown in Fig. 2, the clutch is in a slow speedposition. If it is desired to rotate the grinding wheel I8 at a fastspeed, that is, the normal grinding or truing 'speed. the manuallyoperable control lever 16 is shifted from full line position into thebroken line position 16a whichrocks the gear segment 61 in acounterclockwise direction which, through the gear segment 66, the shaft6|, and the yoked member 66, moves in a clockwise direction to shift theclutch member 55 toward the left (Fig. 2) so that the clutch teeth 58engage the clutch teeth 51 to form a direct driving connection betweenthe shaft 86 and 4|.

To facilitate rotation of the grinding wheel l5 at a very slowrotativespeed below the normal grinding speed, the shaft 36 is provided with aworm 86 which meshes with the worm gear 8|. The worm gear 8| is keyed toa transversely arranged rotatable shaft 82 which is journalled inbearings 83 and 84 which are supported in the casing 28. The forward endof the shaft 82 is rotatably supported in a sleeve 85 which is in turnjournalled in bearings 84 supported in the casing 28. A worm 86 is keyedto the rotatable bushing 85, said parts being arranged so that the worm86 and its supporting bushing 85 may rotate independently of the shaft82. The worm 86 meshes with a worm gear (not shown) whichis supported ona longitudinally extending shaft 81. The shaft 81 is journalled inbearings 88 and 89 supported in the casing 28. A sprocket 96 a is keyedto the shaft 81 and is arranged to transmit its rotatlve power through alink chain 9| to a sprocket 92 which is keyed to the periphery of therotatable sleeve 18.

The worm 86 is arranged so that it may be readily clutched or declutchedfrom the shaft 82. A clutch member 93 is slidably keyed on the shaft 82and is provided with clutch teeth 94 which are arranged to engage clutchteeth 95 formed integrally on the end of the worm 86. A yoked member 96is supported on the end of a slidably mounted actuating rod 91. The rod9.1 is journalled in a bearing 98 fixedly mounted relative to the casing28. The yoked member 96 has integral shoes which engage a groove 99formed in the periphery of the clutch member 93 so that endwise movementof the rod 91 serves to throw the clutch teeth 94 into engagement withthe clutch teeth 95 so that rotary motion of the shaft 82 will betransmitted to rotate the worm 86 or to move the clutch teeth into adisengaged posi tion (Fig. 2). The clutch member 93 is normally held ina disengaged position by means of a spring I66 which surrounds the rod91 and is interposed between the bearing 98 and a collar ml which ismounted on the rod 91. The clutch shifting rod 91 may be actuatedmanually to throw the clutch member 93 into engagement with its clutchteeth 94 engaging the clutch teeth 95 so as to transmit a rotary motionto the worm 86. As illustrated (Fig. 2), a flexible cable I62 isconnected by means of a stud I63 with the projecting front end of theclutch shifting rod 91. The cable I62 passes over rotatably mountedgrooved idler pulleys I64 and I65 which are supportedby studs I66 andI61, respectively. The studs I66 and I61 are supported in brackets whichare fixedly mounted on the housing 6. A slidably mounted actuating knob68 is connected to the forward end of the cable I62. A locking screw I69is provided for locking the actuating knob in a forward position to holdthe clutch member 93 in engagement when desired.

Spindle reciprocating mechanism in either a plunge-cut grindingoperation or a finishing operation where the grinding wheel I is heldstationary or rotated at a very slow speed, it is desirable to provide agrinding wheel spindle reciprocating mechanism whereby the grindingwheel spindle I6 may be reciprocated axially within its bearings I1 andI0. As illustrated in the drawings, a wheel spindle reciprocatingmechanism is contained within a housing IIO which is mounted on theupper portion of the wheel slide II. An eccentric III' is formedintegral with a rotatable sleeve H2. The sleeve H2 is rotatablyjournalled in bearings II3 supported in housing Md. The sleeve H2 ispreferably drivingly con nected with the shaft 82 by means of a key II4,thus forming a telescopic driving connection between the shaft 82 andthe sleeve II2 which facilitates adjustment of the casing 28 intensioning the grinding wheel driving belt 44. The eccentric III isconnected by a connecting rod II5 with a stud IIB carried by an arm II1which is pivotally supported on a fulcrum stud H0. A frame IId which issubstantially of a C-shaped cross section is formed integral with thearm H1 and is supported at its outer end by fulcrumed studs lid and Hi.When the eccentric III is rotated by the shaft I32, an oscillatingmotion will be transmitted by the connecting rod I I5 to oscillate thearm I II and the frame I I9 about the fulcrum studs I and IN. Theopposite sides of the p-shaped frame H0 are provided with substantiallyvertically extending grooves I22 and iii which support slide blocks I24and I25, re-

spectively. The slide blocks I24 and I25 support the trunnion ends I20and I21 of a rectangularly shaped slide block I23 which is slidablypositioned within an elongated slot I29 in a rock arm I30 (Fig. 3). Therock arm I30 is pivotally supported on a shaft I3I which is journalledin suitable bearings in the wheel slide I I. The rock arm I30 isprovided with an enlarged ring-shaped portion which surrounds the wheelspindle I0 and pivotally supports a collar I32 which is provided withtrunnions I33 and I34 projecting into bearing apertures in diametricallyopposite sides of the enlarged portion of the rock arm I30. The collarI32 is supported between the fixed collar I35 and an adjustable thrustcollar I36 carried by the wheel spindle I6 and serves to provide an endthrust bearing for the collar I32, said parts being arranged so thatwhen the lever or rock arm tilt is oscillated, a reciprocating movementis transmitted to move the wheel spindle I6 axially within itssupporting bearings I1 and I8 to produce a reciprocatory movement of thegrinding wheel I5 during an abrading, honing or finfishing operation.

It is desirable to provide means for adjusting the length of thereciprobatory stroke of the wheel spindle. For example, in theconstruction illustrated in the drawings, a reciprocatory stroke varyingfrom zero up to one-eighth of an inch or more may be obtained. Avertically movable yoke-shaped member I33 (Fig. 6) is verticallyadjustable by means of a rotatable screw I39. The screw I30 is rotatablyjournalled in bearings which are fixedly mounted in the housing '0. Theupper end of the screw I39 is provided with a bevel gear I40 whichmeshes with a bevel gear IdI (Fig. 4) supported on the inner end of arotatable shaft I42, the outer end of which is provided with a manuallyoperable adjusting wheel M3. The vertically adjustable yoke-shapedmember I38 is provided with yoke-shaped arms spindle I44 and I45. Thearms I44 and I45 surround anti-friction ball bearings I40 and I41,respectively, which are supported on the trunnions I28 and I21 of theslide block I28. When the screw I39 is rotated, the member I33 is movedvertically which serves to adjust the slide block I28 relative to theelongated aperture I20 in the rock arm I30 and at the same time adjuststhe slide blocks I24 and I25 relative to the grooves I22 and I23 in thesubstantially C-shaped frame H0 so that the axis of the trunnions I26and I21, respectively, may be moved toward and from the axes of thetrunnions I20 and I2I, respectively, to vary the length of thereciprocatory stroke of the wheel spindle I6. As illustrated in thedrawings, the wheel spindle reciprocating mechanism is shown as adjustedto itsmaximum extent. If it is desired to change the reciprocatorystroke, the screw I39 is rotated by means of the hand wheel I 43 tolower the adjustable member I30 which serves to lower the trunnions I26and I21, respectively, so that they approach the axes of the trunnionsI20 and IEI', thereby reducing the oscillatory motion transmitted to therock arm I30 and thus reducing the reciprocatory movement of the wheelspindle I6 and the grin-ding wheel Iii. If the adjustable member I30 islowered until the axes of the trunnions I23 and I21 coincide with theaxes of the trunnions I20 and I2I, then no movement will be transmittedto the rock arm I30 and the wheel Itwill be held against reciprocatorymovement.

In order that the operator may readily adjust the reciprocatingmechanism for a given stroke, a vertically positioned stud I is mountedon the member I38. The stud I50 is provided with a graduated scale whichis readily visible from the operator's station in front of the machine.A stop screw I5I serves to limit the vertical movement of the stud I50and the member I30.

The operation of this improved machine will be readily apparent from theforegoing disclosure. Assuming the various mechanisms and adjustmentshave been previously made, the machine as illustrated in the drawings isset up for a honing or finishing operation with a stationary wheel whichis automatically indexed when the wheel slide is moved to its rearwardposition automatically to present a fresh grinding face for the nextoperation. The grinding wheel spindle reciprocating mechanism is alsooperative to oscillate or reciprocate the wheel spindle I6 within itsbearings I1 and I8 so as to produce a reciprocatory movement of thegrinding wheel I5.

It will thus be seen that there has been provided by this inventionapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges might be made in the embodiment above set forth, it is to beunderstood that all matter hereinabove set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

I claim:

In a grinding machine having a transversely movable wheel slide, arotatable grinding wheel, a rotatable spindle therefor, bearings on theslide for said spindle, an electric motor, high speed drivingconnections between said motor and spindle to rotate the spindle at anormal grinding speed for a grinding operation, a low speed drivingconnection between said motor and spindie to rotate said spindle at aspeed below the normal grinding speed for a finishing operation, meansincluding a clutch to render either the high or the low speedconnections operative,

means including a second clutch to start and 5 stop said low speeddriving connections to facilitate a. polishing operation with the wheelstationary, and a wheel spindle reciprocating mechanism including arotatable eccentric, direct driving connections between said motor andeccentric to rotate the eccentric at a constant speed, and adjustablelever connections between said eccentric and spindle whereby the spindleis reciprocated at a constant speed through a variable stroke.

CHARLES C. ALVORD.

